Systems and methods for calibrating, operating, and setting a laser diode in a weapon

ABSTRACT

Systems and methods for calibrating, operating, and setting the magnitude of the power of light provided by a laser diode in a conducted electrical weapon (“CEW”). The light of the laser diode assists in targeting by providing a visible indication of the projected point of impact of the tethered electrode of the CEW. The calibration process enables laser diode of a CEW to operate within regional guidelines of the maximum output power of light permitted by a laser. The method further permits the magnitude of the power of the light provided by a laser diode to be set and operated in changing environmental conditions in the field.

FIELD OF INVENTION

Embodiments of the present invention relate to laser diodes.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

Embodiments of the present invention will be described with reference tothe drawing, wherein like designations denote like elements, and:

FIG. 1 is a functional block diagram of a system that creates anenvironment (e.g., ecosystem) for calibrating, transmitting information(e.g., data) related to calibration, and storing information related tocalibration according to various aspects of the present disclosure;

FIG. 2 is a functional block diagram of a handle with its laser diodes;

FIG. 3 is a diagram of the power vs. the current characteristic curvesfor a hypothetical laser diode for a single temperature;

FIG. 4 is a diagram of an implementation of a circuit of the handle ofFIG. 2 for calibrating the magnitude of the power of the light providedby a laser diode;

FIG. 5 is another diagram of the power vs. the current characteristiccurves for a hypothetical laser diode for multiple temperatures of thelaser diode;

FIG. 6 is a flow chart of a method for calibrating the magnitude of thepower of light of a laser diode in a CEW.

FIG. 7 is a flow chart of a method for adjusting the magnitude of thepower of light of a laser diode, after calibration.

FIG. 8 is a diagram of another implementation of a circuit of the handleof FIG. 2 for calibrating the magnitude of the power of the lightprovided by a laser diode;

FIG. 9 is a diagram of another implementation of a circuit of the handleof FIG. 2 for calibrating the magnitude of the power of the lightprovided by a laser diode;

FIG. 10 is a diagram of voltages of the circuit of FIG. 5 whileoperating the laser diode; and

FIG. 11 is a diagram of another implementation of a circuit of thehandle of FIG. 2 for calibrating the magnitude of the power of the lightprovided by a laser diode.

DETAILED DESCRIPTION OF INVENTION

A conducted electrical weapon (“CEW”) is a device that provides astimulus signal through a human or animal target via launchedelectrodes. A stimulus signal inhibits locomotion of the target.Locomotion may be inhibited by interfering with voluntary use ofskeletal muscles and/or causing pain in the target. A stimulus signalthat interferes with skeletal muscles may cause the skeletal muscles tolockup (e.g., freeze, tighten, stiffen) so that the target may notvoluntarily move.

A CEW may include a handle and one or more deployment units (e.g.,cartridges). Deployment units removeably insert into the handle. Adeployment unit includes one or more wire-tethered electrodes that arelaunched by a propellant toward a target to provide the stimulus signalthrough the target. A CEW may include one or more laser diodes forilluminating (e.g., targeting) a predicted point of impact of theelectrodes of the deployment unit.

The disclosure provided herein is not limited to laser diodes thatcooperate with a CEW. The methods and structures disclosed herein areapplicable to any type of weapon (e.g., handgun, rifle, machine gun,cannon) that uses one or more lasers for aiming (e.g., targeting).Further, the methods and structures disclosed herein are not limited toweapons. Any type of device (e.g., laser chalk line, laser pointer,laser detector, holograph generator, lidar equipment, geologicalequipment, remote sensing equipment, seismology equipment, laserscanners, barcode readers) that emits laser light may benefit from usingthe methods and structures discussed herein to calibrate, set, and/oroperate the magnitude of the power of the light provided by the laser.

Lasers may be potentially dangerous/hazardous to human eyesight. Lawsfor a region (e.g., country, state) may restrict the maximum outputpower of visible lasers. Laws for maximum output power of a laser varyby region.

Calibrating output power of a laser enables a CEW to operate within thelimits of the law.

Although the above paragraphs discuss the use of a laser diode by a CEWfor targeting, the disclosure herein is not limited to CEWs and/or laserdiodes for targeting (e.g., aiming). The disclosure herein appliesequally to lasers and/or laser diodes that provide light for anypurpose. The disclosure herein applies equally to targeting devices usedby conventional firearms, laser pointers used to indicate a portion ofan object, lasers used in surgery, eye-targeted lasers to temporarilyimpair vision, holography, or any other use where it is desirable toprovide light at a known power output.

Different regions have different maximum output power for lasers.Calibrating the diodes of a CEW to operate at one output power meansthat the CEW cannot be operated in a region where the law requires alower output power. Calibrating to different maximum output powers meansmaintaining an inventory of different CEWs which is inconvenient. Itwould be a benefit to calibrate a CEW to operate at all powers requiredfor all regions then provide the CEW with region information so it canoperate within the laws of that region.

CEWs are hand-held systems and generally operate using a battery. Itwould be a benefit to operate the laser diodes so as to provide thedesired output power while conserving battery power. The operatingefficiency of a laser diode (i.e. electrical input power versus opticaloutput power) is higher when operating at a higher light power output. Alaser diode may be operated at higher optical output power for greaterefficiency, but have its time of operation (e.g., on, off) controlled sothat the average optical output power is within the permitted lightpower output for the region. By modulating the on-off operation of thelaser diode, the laser diode provides the permitted optical output powerand the average power used by the laser diode is reduced therebyextending battery life without an impact on laser visibility.

A power supply may include a boost (e.g., buck) circuit to provide thevoltage and/or current needed to operate a laser diode.

A laser diode in a CEW may require calibration to ensure that amagnitude of a power of a light provided by the laser diode is less thanor equal to a limit allowed in a region where the handle is operated. ACEW may cooperate with a tester (e.g., a light power meter and acomputer) to calibrate (e.g., measure, adjust, standardize) themagnitude of the power of the light provided by the laser diode to bewithin a predetermined range. A range may have an upper value and alower value. An upper value of a predetermined range may be the limit ofthe magnitude of the maximum light power output for a region. Forexample, the maximum laser power output for the U.S. is 5 mW. Themaximum power output for a laser in Europe is 1 mW. The lower value maybe zero; however, at zero output power, a laser diode does not provideany light. In practice, the lower value should be non-zero. The lowerlimit may be the least amount of power that provides an indication on atarget visible to the user of the CEW. In practice, the lower limit isnot less than 50% of the maximum power output of the region where thelaser diode will be used. Preferably the lower value is about 20% lessthan the upper value.

Calibration of the laser diode output power enables the handle of CEW tooperate the laser diode at a measured output power to comply withregional laws. A CEW may adjust (e.g., retain, increase, decrease) themagnitude of the power of the light delivered by a laser diode.

During calibration, the laser diode of a handle provides its light at aninitial power setting. The tester measures the power of the light andreports the power to the handle. The handle may adjust the magnitude ofthe power provided by the laser diode and ask the tester for anotherreading as to how much power is being provided. The handle includes aphoto diode. The photo diode may be packaged with the laser diode as anintegrated unit (e.g., component). The light from the laser diode isdetected by a photo diode. A current through the photo diode is relatedto the magnitude of the power of the light provided by the laser diode.The current through the photo diode flows through a resistor, so thevoltage across the resistor is also related to the output power of thelaser diode.

Because the tester is periodically calibrated using accurate measurementinstruments, the tester accurately measures and reports the power of thelight provided by the laser diode. So, when the tester reports that themagnitude of the power of the light provided by the laser diode is at ornear the desired value, the handle knows that the laser is providingthat amount of power. Further, the handle knows that the voltage acrossthe resistor indicates that the laser diode is providing light at thedesired power. The handle stores the value of the voltage across theresister as a golden voltage, because whenever the voltage across theresistor is equal to that value, the laser diode is providing thecalibrated power of light.

A handle and a tester may cooperate to get a golden voltage for theoutput power of the diode for every region in the world. A goldenvoltage may be used by a handle to set the optical output of a laserdiode while the CEW is being used in the field. The golden voltage usedby the handle to set the optical output of the laser diode may beselected so that the laser diode provides the light power outputappropriate for the region in which the CEW is operating.

A handle may communicate with a server, such as an evidence managementserver, to receive information regarding the maximum light power for theregion in which the handle is being used. A handle may communicate witha server directly using any conventional communication protocol. Ahandle may communicate with a server via another electronic system suchas a cell phone or a tablet.

System 100 creates an ecosystem for calibrating a handle of a CEW.System 100, also referred to as ecosystem 100 enables handle 110 tocooperate with tester 130 to calibrate handle 110. Ecosystem 100, shownin FIG. 1, may include handle 110, tester 130, communication link 140,communication link 170, network 150 and server 160.

As discussed above, a handle in cooperation with a deployment unitlaunches one or more electrodes to provide a current through a target toimpede locomotion of the target. A handle may operate a deployment unitto launch the electrodes of the deployment unit toward a target. Ahandle operates one or more laser diodes to illuminate a predicted pointof impact of one or more electrodes on the target.

The ecosystem enables handle 110 to cooperate with tester 130 viacommunication link 140 to transfer data from light power meter 132.Ecosystem 100 further enables handle 110 to communicate viacommunication circuit 224 with server 160 over a communication link 170.One or more laser diodes may be coupled to handle 110 while handle 110interacts with tester 130.

A handle may control a magnitude of the power of light provided by alaser diode. A handle may communicate with other devices in theecosystem. A handle may detect physical properties (e.g., voltage,current, time). A handle may store data (e.g., information). A handlemay provide a report. The information reported by a handle may includeoperating state and status of a deployment unit.

Handle 210 includes green laser 212, red laser 216, red laser 218,processing circuit 220, memory 222, communication circuit 224, bus 226,and signal generator 228.

The angle of the path of the light provided by red laser 216 differsfrom the path of the light from green laser 212 by eight degrees (8°).The angle of the path of the light provided by red laser 218 differsfrom the path of the light from green laser 212 by twelve degrees (12°).The path of the lights form the lasers and their relative anglescorresponds to the predicted path of the electrodes of a deploymentunit.

A laser diode is a semiconductor device that emits light. A laser diodeemits a beam of coherent monochromatic light. A beam of light from alaser is spatially coherent thereby providing a narrow beam of light(e.g., collimated) that stays narrow for a distance. A laser diodeincludes an optical amplifier for generating the light. A laser may beused in a CEW to enhance targeting. A laser diode may be coupled to aCEW. The beam of light from the laser may be aligned with direction oftravel of an electrode launched from the CEW.

The laser may indicate a location on a target of likely impact of theelectrode. The light for a laser is visible during the day or at night.Since the light of a laser beam is highly collimated, the laser lightappears as a small spot (e.g., dot) on a target even at long distances.A user may use the laser to perform the function of a sight for aiming.A user may aim the CEW to position the spot at a desired location on thetarget thereby aligning the likely direction of flight of the electrodeto the spot on the target. The position of the spot on the target maynot account for factors (e.g., electrode drop, windage) that may causethe electrode to diverge during flight. The laser beam provides anestimated location of impact of the electrode.

Many laser sights use a red laser diode. The green laser may be morevisible than the red laser in bright lighting conditions because, forthe same wattage, green light appears brighter to the human eye than redlight.

A processing circuit includes any circuitry and/or electrical/electronicsubsystem for performing a function. A processing circuit may includecircuitry that performs (e.g., executes) a stored program. A processingcircuit may include a digital signal processor, a microcontroller, amicroprocessor, an application specific integrated circuit, aprogrammable logic device, logic circuitry, state machines, MEMSdevices, signal conditioning circuitry, communication circuitry, aconventional computer (e.g., server), a conventional radio, a networkappliance, data busses, address busses, and/or a combination thereof inany quantity suitable for performing a function and/or executing one ormore stored programs.

A processing circuit may further include conventional passive electronicdevices (e.g., resistors, capacitors, inductors) and/or activeelectronic devices (op amps, comparators, analog-to-digital converters,digital-to-analog converters, current sources, programmable logic). Aprocessing circuit may include conventional data buses, output ports,input ports, timers, memory, and arithmetic units.

A processing circuit may provide and/or receive electrical signalswhether digital and/or analog in form. A processing circuit may provideand/or receive digital information (e.g., data) via a conventional bususing any conventional protocol. A processing circuit may receiveinformation, manipulate the received information, and provide themanipulated information. A processing circuit may store information andretrieve stored information. Information received, stored, and/ormanipulated by the processing circuit may be used to perform a functionand/or to perform a stored program.

A processing circuit may control the operation and/or function of othercircuits and/or components of a system. A processing circuit may receivestatus information regarding the operation of other components (e.g.,status, feedback). A processing circuit may perform calculations (e.g.,operations) with respect to the status information. A processing circuitmay provide commands to one or more other components in accordance withcalculations. For example, a processing circuit request the status of acomponent, analyze the status, and command components to startoperation, continue operation, alter operation, suspend operation, orcease operation. Commands and/or status may be communicated between aprocessing circuit and other circuits and/or components via any type ofbus including any type of conventional data/address bus.

A processing circuit may generate a signal. A processing circuit mayprovide a signal to another component and/or circuit. A processingcircuit may provide a signal having one or more characteristics (e.g.,frequency, amplitude, pulse width, number of pulses, repetition rate ofpulses). A processing circuit may provide a pulse width modulated(“PWM”) signal. A processing circuit may alter one or morecharacteristics of a signal in accordance with the status of anothercomponent and/or circuit.

A computer-readable medium may store, retrieve, and/or organize data.Computer-readable medium includes any storage medium that is readableand/or writable by an electronic machine (e.g., computer, computingdevice, processor, processing circuit, transceiver). Storage mediumincludes any devices, materials, and/or structures used to place, keep,and retrieve data (e.g., information). A storage medium may be volatileor non-volatile. A storage medium may include any semiconductor medium(e.g., RAM, ROM, EPROM, Flash), magnetic medium (e.g., hard disk drive),medium optical technology (e.g., CD, DVD), or combination thereof.Computer-readable medium includes storage medium that is removable ornon-removable from a system. Computer-readable medium may store any typeof information, organized in any manner, and usable for any purpose suchas computer readable instructions, data structures, program modules, orother data. A data store may be implemented using any conventionalmemory, such as ROM, RAM, Flash, or EPROM. A data store may beimplemented using a hard drive.

A memory includes any digital circuitry for storing program instructionsand/or data. Storage may be organized in any conventional manner (e.g.,program code, buffer, circular buffer, data structure). Memory may beincorporated in and/or accessible by a transmitter, a receiver, atransceiver, a sensor, a controller, and a processing circuit.

A data store includes any suitable device configured to store data foraccess by an electronic machine. A data store receives data. A datastore retains (e.g., stores) data. A data store retrieves data. A datastore provides data for use by a system, such as an engine. A data storemay organize data for storage. A data store may organize data as adatabase for storage and/or retrieval. The operations of organizing datafor storage in or retrieval from a database of a data store may beperformed by a data store. A data store may include a repository forpersistently storing and managing collections of data. A data store maystore files that are not organized in a database. Data in a data storemay be stored in a computer-readable medium.

A communication circuit may transmit and/or receive information (e.g.,data). A communication circuit may transmit and/or receive (e.g.,communicate) information via a wireless link and/or a wired link. Acommunication circuit may communicate using wireless (e.g., radio,light, sound, vibrations) and/or wired (e.g., electrical, optical)mediums. A communication circuit may communicate using any wireless(e.g., Bluetooth, ZigBee, WAP, Wi-Fi, NFC, IrDA, GSM, GPRS, 3G, 4G)and/or wired (e.g., USB, RS-232, Firewire, Ethernet) communicationprotocols. Short-range wireless communication (e.g. Bluetooth, ZigBee,NFC, IrDA) may have a limited transmission range of approximately 20cm-100 m. Long-range wireless communication (e.g. GSM, GPRS, 3G, 4G,LTE) may have a transmission ranges up to 15 km. A communication circuitmay receive information from a processing circuit for transmission. Acommunication circuit may provide received information to a processingcircuit.

A communication circuit may include a transmitter and a receiver. Acommunication circuit may further include a decoder and/or an encoderfor encoding and decoding information in accordance with a communicationprotocol. A communication circuit may further include a processingcircuit for coordinating the operation of the transmitter and/orreceiver or for performing the functions of encoding and/or decoding.

A communication circuit in one system (e.g., vehicle computer) maycommunicate with a communication circuit in another system (e.g.,equipment). Communications between two systems may permit the twosystems to cooperate in performing a function of either system.

A communication link provides a medium for communication. Acommunication link may be suitable for a communication protocol. Acommunication link may be a conduit (e.g., channel) for communicationbetween two systems.

Communication links 170 between handle 110 and server 160 and, network150 may be any conventional communication link that communicates (e.g.,transmit, receive) data using any conventional wired or wirelessprotocol.

Communication link 170 may be established as peer-to-peer links or linksestablished via an access point or base station. Communication link 170may be provided by short-range, lower power communication circuits(e.g., transceivers, transmitter, receiver). Communication link 170 maybe provided by a longer-range, higher power communication circuit.

Preferably, communication link 170 is a high speed link for transferringlarge amounts of data to evidence management system (e.g. e.com) server160.

A transceiver includes any circuitry for maintaining a communicationlink with one or more other transceivers. A transceiver may transmitand/or receive data via the communication link. Any conventionalsignaling technologies and communication technologies (e.g., protocols,standards, protocol stacks) may be used to establish and/or maintain thecommunication link. Any conventional signaling technologies andcommunication technologies may be used to transmit and/or receive datavia the communication link. Integrated circuitry is preferred for smallsize and low power consumption. Programmable circuits using conventionalprogram development technology may be used. To support one or morelinks, a transceiver may be coupled to a controller for complying withprotocols, managing message buffers, and following communication logic(e.g., to retry when messages are not acknowledged, to join an ad hocnetwork).

A local area transceiver, as used herein, is a type of transceiver thatemploys relatively low power transmissions and relatively lowsensitivity receivers to accomplish communication over one or morelinks. Each link may have a distance shorter than 6 feet (2 m). Theseshort distance capabilities are useful for communications amongelectronics intended to be used in concert by one person. Higher powertransmissions and relatively higher receiver sensitivity may be usedwhere interference with other systems is otherwise unlikely.

A wide area transceiver, as used herein, is a type of transceiver asdiscussed above that employs relatively high power transmissions andrelatively high sensitivity receivers to accomplish communication overone or more links. Each link may have a distance in the range of 10 feet(3 m) to 2000 feet (600 m).

A tester may detect (e.g., witness, discover) physical properties (e.g.,intensive, extensive, isotropic, anisotropic). Physical propertiesinclude luminance. A tester may detect a physical property and/or achange in a physical property directly and/or indirectly. A tester maydetect a quantity, a magnitude, and/or a change in a physical property.A detector may detect a physical property and/or a change in a physicalproperty directly and/or indirectly. A tester may detect one or morephysical properties and/or physical quantities at the same time or atleast partially at the same time. A tester may deduce (e.g., infer,determine, calculate) information related to a physical property. Aphysical quantity may include an amount of time and an elapse of time.

A tester may transform a detected physical property to another physicalproperty. A tester may transform (e.g., mathematical transformation) adetected physical quantity. A tester may relate a detected physicalproperty and/or physical quantity to another physical property and/orphysical quantity. A tester may detect one physical property and/orphysical quantity and deduce another physical property and/or physicalquantity.

A tester may include any circuit for detecting, transforming, relating,and deducing physical properties and/or physical quantities. Forexample, a tester may include a light detector. A tester may include aprocessing circuit for calculating, relating, and/or deducing. Aprocessing circuit of a tester may determine luminous energy, luminousflux, luminous power, luminous intensity, and luminous energy density.

A tester may quantify and/or describe a physical property. A tester mayprovide a report regarding a physical property.

For example, tester 130 includes light power meter 132, computer 136,and bus 134. Handle 110 may cooperate with tester 130 to measure themagnitude of the energy of the light provided by one or more laserdiodes in handle 110. A laser diode of handle 110 may provide a beam oflight to tester 130. Tester 130 may measure the magnitude of the powerof the light provided by the laser diode. Tester 130 may report thedetected power of the laser light to handle 110 via communication link140.

Tester 130 may measure the instantaneous and/or average power of thelight provided by a laser diode of handle 110. Tester 130 may report theinstantaneous and/or average power of the light to handle 110. Handle110 may coordinate its operation with tester 130 to provide light formeasurement by tester 130. Handle 110 may cooperate with tester 130 sothat handle 110 may calibrate the light power output of a laser diode ofhandle 110. Handle 110 may control (e.g., initiate, terminate, continue,repeat) the operation of tester 130 to detect, measure, and/or reportthe magnitude of the power of the light provided by a laser diode ofhandle 110. Responsive to reports from tester 130, handle 110 maycalibrate the light power output of a laser diode of handle 110.

A light power meter may detect a light. A light power meter may measurea magnitude of the power of a light. A light power meter may measure amagnitude of an average power of a light. A light power meter may reportthe magnitude of the power of detected light. A light power meter mayprovide information about light power measurements to a computer.

A computer includes any electronic machine as discussed above. Acomputer may include a conventional computer. A computer may control theoperation of tester 130. A computer may communicate with light powermeter 132 via bus 134. Computer 136 may receive information about lightpower measurements performed by light power meter 132. Computer 136 maycontrol the operation of light power meter 132. A computer maycommunicate with handle 110 with a communication circuit. A computer maysend messages to and receive messages from handle 110.

Bus 134 may include any conventional bus (e.g. UART, SPI, I2C, or USB).

A server may store information related to one or more regions, and/orinformation related to one or more agencies (e.g., security agency,police agency).

A server may receive information. A server may process (e.g., calculate,transform) information. A server may provide information. A server mayprovide transformed information. A server may communicate with otherelectronic systems. A server may communicate with other electronicsystems via a network.

A server may receive and/or determine a geographic location of a weapon.A server may have information regarding the region where a particularCEW is located. A server may relate the geographic location of a weaponto a region where the weapon is located. A server may have informationregarding the maximum output power permitted by a laser diode in aregion. A server may determine a maximum power output of a laser diodefor a region. A server may inform a weapon of the maximum power outputfor the laser diode of the weapon in accordance with the region wherethe weapon is located. A server may prepare and/or provide a report. Aserver may report the region of a weapon. A server may report themaximum power output assigned by the server to a weapon.

Ecosystem 100 further enables handle 110 to communicate viacommunication circuit 124 with server 160 over a communication link 170.A CEW may provide information to a server. Information that a CEWprovides to a server may include the geographic location of the CEWand/or the identifier of the CEW. A CEW may receive information from aserver. A CEW may perform an operation in response to the informationreceived from a server. A CEW may conform (e.g., set) the output powerof a laser diode of the CEW responsive to information received from aserver.

For example, server 160 performs the functions of a server discussedabove. Server 160 may include region engine 166, agency data store 168,region data store 164, and network interface 162.

An engine may perform one or more operations of a server. An engine mayperform one or more functions or a single function. An engine may accessstored data to perform an operation and/or function. An engine maygenerate (e.g., produce) data for storage.

The term “engine” as used herein refers to, in general, circuitry, logicembodied in hardware and/or software instructions executable by aprocessor of a computing device. Circuitry includes any circuit and/orelectrical/electronic subsystem for performing a function. Logicembedded in hardware includes any circuitry that performs apredetermined operation or predetermined sequence of operations.Examples of logic embedded in hardware include standard logic gates,application specific integrated circuits (“ASICs”), field-programmablegate arrays (“FPGAs”), microcell arrays, programmable logic arrays(“PLAs”), programmable array logic (“PALs”), complex programmable logicdevices (“CPLDs”), erasable programmable logic devices (“EPLDs”), andprogrammable logic controllers (“PLCs”). Logic embodied in (e.g.,implemented as) software instructions may be written in any programminglanguage, including but not limited to C, C++, COBOL, JAVA™, PHP, Perl,HTML, CSS, JavaScript, VBScript, ASPX, HDL, and/or Microsoft .NET™programming languages such as C#. The software for an engine may becompiled into an executable program or written in an interpretedprogramming language for execution by a suitable interpreter or virtualmachine executed by a processing circuit. Engines may be callable (e.g.,executable, controllable) from other engines or from themselves.

Generally, the engines described herein can be merged with otherengines, other applications, or may be divided into sub-engines. Enginesthat are implemented as logic embedded in software may be stored in anytype of computer-readable medium. An engine may be stored on andexecuted by one or more general purpose computers, thereby creating aspecial purpose computer configured to perform the functions of (e.g.,provide) the engine.

The devices and systems illustrated herein may include one or morecomputing devices configured to perform the functions of an engine,though the computing devices themselves have not been illustrated inevery case for the sake of clarity. An example of a computing device isprovided below.

Region engine 166 may perform the functions of an engine as discussedabove. Region engine 166 may access information from agency data store168 and/or region data store 164. Region engine 166 may store data inagency data store 168 and/or region data store 164. Region engine 166may receive and/or determine a geographic location of a weapon. Regionengine 166 may determine a region in which a weapon is located. Regionengine 166 may relate the geographic location of a weapon to a regionwhere the weapon is located. Region engine 166 may determine a maximumpower output of a laser diode of the weapon in accordance with theregion where the weapon is located. Region engine 166 may transmitinformation to a weapon, directly or indirectly. Region engine 166 mayreceive information from a weapon, directly or indirectly. Region engine166 may cooperate with network interface 162 to communicate with aweapon. Region engine 166 may inform a weapon of the region in which theweapon is located. Region engine 166 may inform a weapon of the maximumpermissible power output of the light from a laser diode of the weaponfor the region in which the weapon is located.

Region engine 166 may provide a report. Region engine 166 may provide areport to an agency. Region engine 166 may report the region of aweapon. Region engine 166 may report the maximum power output assignedby the server to a weapon.

Region engine 166 may be implemented using a computing device.

As understood by one of ordinary skill in the art, a “data store” asdescribed herein may be any suitable device configured to store data foraccess by a computing device. A data store receives data. A data storeretains (e.g., stores) data. A data store retrieves data. A data storeprovides data for use by a system, such as an engine. A data store mayorganize data for storage. A data store may organize data as a databasefor storage and/or retrieval. The operations of organizing data forstorage in or retrieval from a database of a data store may be performedby a data store. A data store may include a repository for persistentlystoring and managing collections of data. A data store may store filesthat are not organized in a database. Data in a data store may be storedin a computer-readable medium.

One example of a data store suitable for use with the high capacityneeds of a server is a highly reliable, high-speed relational databasemanagement system (“RDBMS”) executing on one or more computing devicesand accessible over a high-speed network. However, any other suitablestorage technique and/or device capable of quickly and reliablyproviding the stored data in response to queries may be used, such as akey-value store and an object database.

A data store may be implemented using any computer-readable medium.

For example, agency data store 168 may receive and store informationrelated to one or more agencies. Information related to an agency mayinclude weapons owned and/or controlled by the agency, weapons deployedby an agency, identifiers (e.g., serial numbers) of weapons owned and/orcontrolled by an agency, geographic location of an agency, geographicextent of service of an agency, geographic location of deployment of aweapon, and/or selected power output of the laser diode of the weapon.

Region data store 164 may receive and store information related to oneor more regions. Information related to a region may include ageographic location of the region, GPS coordinates of the boundaries ofa region, GPS coordinates of particular locations in a region, a maximumpower output of light from a laser diode permitted in the region, and/orfrequencies of laser lights permitted in the region.

A network interface enables a system or a computing device, as discussedbelow, to communicate with other devices and/or systems over a network.The functions of a network interface may be performed by circuits, logicembedded in hardware, software instructions executable by a processor,or any combination thereof. The functions performed by a networkinterface enable a computing device to communicate with another device.The functions performed by a network interface, whether using hardwareor software executed by a processor, may be referred to as services. Adevice may request the services of a communication interface tocommunicate with a computing device.

A network interface may communicate via wireless medium and/or a wiredmedium. A network interface may include circuits, logic embedded inhardware, or software instructions executable by a processor (e.g.,wireless network interface) for wireless communication. A networkinterface may include circuits, logic embedded in hardware, or softwareinstructions executable by a processor (e.g., wired network interface)for wired communication. The circuits, logic embedded in hardware, orsoftware used for a wireless network interface may be the same in wholeor in part as the circuits, logic embedded in hardware, or software usedfor a wired network interface. A network interface may communicate usingany conventional wired (e.g., LAN, internet) or wireless communication(e.g., Bluetooth, Bluetooth Low Energy, Wi-Fi, ZigBee, 2G, 3G, LTE,WiMAX) protocol.

A network enables electronic systems to exchange data (e.g.,information). A network may include nodes. A communication link (e.g.,data link) permits the transfer of information between nodes of thenetwork. A node of a network may include a server and/or a handle. Aserver and/or a handle may communicate (e.g., transmit, receive) viaother nodes and communication links of the network.

An electronic system may send or receive data. An electronic system maybe a node in a network. An electronic system may be stationary orportable. An electronic system may present information on a display ofthe electronic system. An electronic device may receive information froma user via a user interface. An electronic system may performcalculations and/or analyze data. An electronic system may perform acalculation and/or analyze data and provide (e.g., transmit) the resultto another system. An electronic system may communicate with othersystems via a wired or wireless connection. An electronic device mayinclude a smart phone carried by a user. An electronic system mayinclude a tablet, a computer, and/or a mobile data terminal in avehicle. An electronic system may operate as an intermediary between aCEW and a node of the network, such as a server.

Setting the power of the light provided by a laser diode may beaccomplished by setting the operating point of the laser diode. Theoperating point of a laser diode refers to the point on a characteristiccurve where the laser diode operates. A characteristic curve of a laserdiode relates the magnitude of the power of light provided by the laserdiode to the current through (e.g., drawn by) the laser diode.

Characteristic curve 310 of an example laser diode shows therelationship between the current that flows through the laser diode(x-axis) and the power of the light provided by the laser diode(y-axis). Characteristic curve 310 shows the relationship between thelight power output and the current of the laser diode at 25 degreesCelsius. The relationship between light power and current is temperaturedependent. The temperature dependence of a laser diode is discussedbelow.

An operating point of the laser diode is defined as a point oncharacteristic curve 310. The point of characteristic curve 310identifies the light power for the current. For example, at operatingpoint 320, the current through the example laser diode is 58 milliamps(“mA”). While the laser diode operates at 25 degrees Celsius and acurrent of 58 mA flows through the laser diode, the power of the lightprovided by the laser diode is 5 milliwatts (“mW”). While the laserdiode operates at operating point 330, the current through the laserdiode is 65 mA and the power of the light provided by the diode is 10mW.

The operating point of a laser diode may be set by a circuit. A circuitfor setting the operating point of a laser diode may include circuitryfor establishing a voltage across the laser diode. A circuit for settingthe operating point of a laser diode may include a processing circuit. Aprocessing circuit may set, at least in part, the operating point of alaser diode. A circuit for setting the operating point of a laser diodemay include a feedback circuit. A processing circuit may detect feedbackfrom a circuit for setting an operating point. A processing circuit mayperform a function in accordance with feedback. An operating circuit mayset an operating point of a laser diode at least in part in accordancewith feedback from a circuit for setting the operating point of a laserdiode.

Circuit 400 is an example of a circuit that sets the operating point ofa laser diode and detects the magnitude of output power of the light ofthe laser diode. Circuit 400 performs the functions of a circuit thatsets the operating point of a diode as discussed above. Circuit 400performs the functions of a detector circuit discussed herein. Circuit400 includes processing circuit 220, operating point circuit 430, anddetector circuit 460. Processing circuit 220 performs the functions of aprocessing circuit discussed above.

An operating point circuit sets the current that flows through a laserdiode. An operating point circuit sets an operating point of a laserdiode. An operating point circuit may be controlled, at least in part bya processing circuit. A processing circuit may provide a signal to anoperating point circuit. An operating point circuit may set theoperating point of a laser diode in response to the signal from theprocessing circuit. A signal from a processing circuit may include apulse-width modulate (“PWM”) signal. An operating point of a laser diodemay relate to a duty cycle of a PWM signal.

Duty cycle describes the ratio or proportion of on time or pulse widthto the total period of the PWM signal. A low duty cycle corresponds to ashort pulse width. A PWM signal may be used to control the powersupplied to an electronic device. The average value of the voltage orcurrent provided to the electronic device is determined by the amount oftime the electronic device is turn on to the amount of time it is turnedoff. The longer the electronic device is on compared to the off periods,the higher the total power supplied to the electronic device. A PWMsignal may control a switch to control the voltage or current providedto the electronic device. The duty cycle of the PWM signal determinesthe voltage or the current supplied to the electronic device, which inturn determines the average power provided to the device.

For example, operating point circuit may include transistor 434,inductor 432, diode 436, capacitor 438, and laser diode 450. Processingcircuit 220 sets the operating point of laser diode 450 by controllingthe voltage on node 440. The operating point of laser diode 450determines the magnitude of the power of the light provided by the laserdiode 450 as discussed above.

In example circuit 400, processing circuit 220 provides a PWM signal tonode 480. Node 480 drives the gate of transistor 434. Transistor 434,inductor 432, and diode 436 perform the function of a boost converterthat provides the voltage across laser diode 450 which determines thecurrent that flows through laser diode 450. The output of the boostconverter drives node 440. The output voltage of the boost converter atnode 440 is related to the duty cycle of the PWM signal on node 480.Processing circuit 220 may increase or decrease the output voltage ofthe boost converter on node 440 by increasing or decreasing respectivelythe duty cycle of signal 480.

A processing circuit may set the output power of the light of a laserdiode by using a circuit to set the operating point of the laser diodeas discussed above. The operating point of a laser diode is temperaturedependent. Characteristic curves of an example laser diode as a functionof temperature are shown in FIG. 5. Characteristic curves 510, 520, and530 show the relationship between the power output of the light of alaser diode (y-axis) and the current of the laser diode (x-axis) at 5,25, and 45 degrees Celsius respectively. Characteristic curves 510, 520,and 530 show that for a given current through the laser diode, theoutput power of the light increases as the temperature decreases andvice versa. For example, if the current through the laser diode is 55mA, the power output at 45, 25, and 5 degrees Celsius is about 1 mW, 3mW, and 10 mW and the diode operates at operating points 572, 574, and576 respectively.

The effect of temperature may also be assessed from the perspective ofmaintaining a particular output power over temperature. To maintain anoutput power of about 5 mW, the current through the laser diode wouldneed to be 48 mA, 58 mA, and 69 mA at 5, 25, and 45 degrees Celsiusrespectively. In other words, to maintain about the same output power ofthe laser diode, the amount of current through the diode would need tobe increased as the temperature increases and vice versa. For example,at 5, 25, and 45 degrees Celsius respectively the current through thediode to provide output power of about 5 mW is 48 mA (operating point540), 58 mA (operating point 550), and 69 mA (operating point 560)respectively.

A detector circuit detects the magnitude of output power of the lightfrom a laser diode. A detector circuit may provide a signal that isrelated to the magnitude of output power of the light from the laserdiode. A signal may include a voltage and/or a current. A detectorcircuit may provide the signal to a processing circuit. A detectorcircuit may be temperature insensitive.

The operating point of a laser diode may be adjusted responsive totemperature. The operating point of a laser diode may be adjusted tomaintain about the same current through the laser diode overtemperature. The operating point of a laser diode may be adjusted tomaintain about the same output power of light from the laser diode overtemperature. The operating point of the laser diode may be adjustedresponsive to detecting. A processing circuit may use a signal from adetector circuit for adjusting an operating point of a laser diode.Operating point circuit 430 may set the operating point of a laser diodeas discussed above.

A processing circuit may cooperate with a tester to relate (e.g.,associate) a magnitude of an output voltage of a detector circuit to ameasured magnitude of output power of the light provided by the laserdiode. The process of relating a magnitude of an output voltage from adetector circuit to a measured magnitude of output power of light may bereferred to as calibrating the output power of the light from the laserdiode.

During calibration, a processing circuit may cooperate with a tester tocalibrate the output power of the light from the laser diode. Aprocessing circuit may set the operating point for a laser diode. At theoperating point for the temperature of the laser diode, the laser diodeprovides a light having a magnitude of power. The tester may measure themagnitude of the power of the light provided by the laser diode. Aprocessing circuit may receive a message from a tester that reports themagnitude of the output power of the light from the laser diode. Aprocessing circuit may measure the magnitude of the output voltage fromthe detector circuit. A processing circuit may relate the reportedmagnitude of output power of the light to the magnitude of the voltagefrom the detector circuit.

For a detector circuit that is temperature insensitive, each time thelaser diode provides light at a particular magnitude of power, themagnitude of the output voltage of the detector circuit will be aboutthe same regardless of temperature. For example, suppose that thetemperature of the laser diode is about 45 degrees Celsius and theprocessing circuit sets the current through the laser diode to be about55 mA so that the laser diode operates at operating point 572. Atoperating point 572, suppose that the output voltage of the detector isV1.

Now suppose that the temperature drops to 25 degrees Celsius so that theoperating point of the laser diode moves to operating point 574. Themagnitude of the output power of the light from the laser diode is nowabout 3 mW. Since the operation of the detector circuit is temperatureinsensitive, the detector circuit will accurately detect the magnitudeof output power, but since the magnitude of output power has increased,the voltage output from the detector circuit will no longer be V1because the voltage V1 is produced each time the magnitude of outputpower of the laser diode is 1 mW. At 25 degrees Celsius, the processingcircuit will need to adjust the current through the laser diode to beabout 46 mA, operating point 578, so that the magnitude of output poweris about 1 mW. At 25 degrees Celsius, if the processing circuit adjuststhe operating point of the laser diode to be operating point 578, thedetector circuit will detect the magnitude of output power of the lightfrom the laser diode, now about 1 mW, and the output voltage from thedetector circuit will be V1.

Circuit 460 is an example of a detector circuit. Detector circuit 460includes photo detector 462, capacitor 466, and resistor 464.

Photo detector 462 detects the light provided by laser diode 450. Thelight from laser diode 450 causes a current to flow through photodetector 462. The current through photo detector 462 is related to themagnitude of the power of the light received by photo detector 462.

The current that flows through photo detector 462 also flows throughresistor 464. The voltage across resistor 464 is the voltage at node470. Processing circuit 220 may measure (e.g., detect, sample) themagnitude of voltage at node 470. The voltage on node 470 is referred toherein as the output voltage of the detector circuit.

Capacitor 466 cooperates with resistor 464 to form an RC circuit havinga time constant. The time constant of the RC circuit may be larger thanthe period of the PWM signal provided by processing circuit 220 at node480. The time constant of the RC circuit may be an order of magnitudegreater than the period of the PWM signal. The RC circuit reduces thevoltage ripple on node 470 that may be induced by the modulated signalon node 480.

Because the current induced by the magnitude of light detected by photodetector 462 is insensitive to temperature, the current provided byphoto detector 462 will be related to the magnitude of the power oflight provided by laser diode 450 regardless of the operatingtemperature of laser diode 450.

Since the current through photo detector 462 is related to the magnitudeof the power of the light from laser diode 450 and flows throughresistor 464, the voltage across resistor 464 is related to themagnitude of the power of the light from laser diode 450.

The voltage across resistor 464, voltage at node 470, is the outputvoltage of the detector circuit measured the processing circuit 220.Processing circuit 220 sets the magnitude of the power of light providedby laser diode 450 responsive to monitoring the output voltage of thedetector circuit. As the magnitude of the light power from laser diode450 varies over temperature, processing circuit 220 may detect thechanges and adjust the PWM duty cycle of the operating point circuit tomaintain the magnitude of the power of the light provided by laser diode450 at a desired value.

A processing circuit may set the operating point of a laser diode toprovide a predetermined magnitude of power of light or a predeterminedrange of magnitude of power of light. A predetermined magnitude of powerof light is referred to herein as a predetermined power. A predeterminedrange of magnitude of power of light is referred to herein as apredetermined range. A predetermined power or a predetermined range mayrelate to a maximum power of light for a region.

A predetermined power or range may be included in the stored programexecuted by a processing circuit or stored in a memory. A predeterminedpower or range may be provided to a processing circuit by the testerduring calibration and stored in a memory of a handle. A predeterminedpower or range may be provided to a processing circuit by a server andstored in a memory of a handle. A predetermined power or range may beprovided to a processing circuit and/or updated by any combination ofthe above. The initial and/or updated values for a predetermined poweror range may be stored in a memory for use by a handle duringcalibration of the handle or operation of the handle in the field. Apredetermined power or range may include values for all regions ofoperation of any handle.

During calibration, a processing circuit of a handle retrieves a value,as discussed above, of a predetermined power. The processing circuitsets an initial operating point of the laser diode and thereby sets aninitial magnitude of the power of the light provided by a laser diode.The laser diode provides the light to the tester. The processing circuitreceives a message from the tester that reports the magnitude of thepower of light as measured by the tester. The processing circuitcompares the magnitude of the power of light as measured by the testerto a predetermined power. The processing circuit adjusts the operatingpoint of the laser diode responsive to comparing. The tester measuresthe magnitude of the power of light and provides another report to thehandle. The processing circuit repeats, adjusting, receiving a report,and comparing until the magnitude of the power of light measured by thetester is about the same as the predetermined power.

When the processing circuit receives a report from the tester that themagnitude of the power of the light provided by the laser diode is at ornear the predetermined power, the handle knows that the laser diode isproviding light at the magnitude of the predetermined power. Further,the processing circuit knows that the magnitude of the output voltagefrom the detector circuit (e.g., the voltage at node 470) relates to thepredetermined power. Once the magnitude of the power of the lightprovided by the laser diode is about the same as the predeterminedpower, the processing circuit stores in memory the value of themagnitude of the output voltage of the detector circuit as a goldenvoltage. The term “golden voltage” means that whenever the outputvoltage of the detector circuit is equal to golden voltage, the laserdiode is providing a calibrated magnitude of power of light. Theprocessing circuit associates that golden voltage to a specificpredetermined power.

A processing circuit may determine the upper and lower golden voltage ofa predetermined range using the calibration method discussed above.

A golden voltage determined during calibration may be used by aprocessing circuit to set the magnitude of the power of light from alaser diode while the CEW is being used in the field. A golden voltagemay be used by a processing circuit to set the magnitude of the power oflight from a laser diode so that the laser diode provides thepredetermined power or power within the predetermined range for theregion in which the CEW is operating.

A golden voltage may be used to maintain the magnitude of the power oflight from a laser diode to be about the same as the predetermined poweror within the predetermined range for the region over variations intemperature of the laser diode.

The magnitude of the power of light from a laser diode is about the sameas a predetermined power when the magnitude of the power of the lightfrom the laser diode is the same as the predetermined power or lieswithin the range of the predetermined power minus 10 percent (10%) ofthe predetermined power. For example, if the predetermined power is 5mW, the magnitude of the power of light from a laser diode is about thesame if the magnitude of the power of light from the laser diode isbetween 4.5 mW and 5 mW.

The magnitude of the power of light from a laser diode is about the sameas an upper value of a predetermined range when the magnitude of thepower of light from a laser diode is the same as the upper value of thepredetermined range or lies within the range of the upper value of thepredetermined range minus 10 percent (10%) of the upper value of thepredetermined range. The same applies to the lower value of apredetermined range.

Because the predetermined power and the predetermined range of oneregion may be different from the predetermined power and thepredetermined range of another region, a handle may be calibrated todetermine and store one or more golden voltages for one or more regions.Table 1 below identifies predetermined power for three differentregions. Table 2 below identifies predetermined power ranges for threedifferent regions. The values of the golden voltages may be differentfor each handle due to variations in components of different handlessuch as the laser diode.

TABLE 1 Examples of Predetermined Power and Golden Voltages for RegionsGolden Golden Voltage for Pre- Voltage for Predetermined determinedPredetermined Power minus Region Power Power 10 percent 1 5 mW V1PV1Pm10 2 3 mW V2P V2Pm10 3 1 mW V3P V3Pm10

The golden voltage for the predetermined power minus 10 percent (e.g.,V1Pm10, V2Pm10, V3Pm10) may be measured during calibration and stored inthe memory of the handle for use when setting the power of light of thelaser diode in the field or it may be calculated using information thatrelates the current through photo detector 462 and the magnitude of thepower of light detected.

TABLE 2 Examples of Predetermined ranges and Golden Voltages for RegionsGolden Golden Voltage for Voltage for Pre- Lower Value of Upper Value ofdetermined Predetermined Predetermined Region Range Range Range 1 3-5 mWV1L V1U 2 1-3 mW V2L V2U 3 0.5-1 mW V3L V3U

When a range is specified for the output power of light for a region, agolden voltage for an upper value and a lower value is determined duringcalibration. For a particular handle, the values for V1L, V1U, V2L, V2U,and V3U may be V2P, V1P, V3P, V2P, V3P respectively from Table 1 becausethe magnitude of the power of the light from the laser diode is thesame.

For example, handle 110 cooperates with tester 130 and possibly server160 to calibrate the magnitude of the power of light from the laserdiode to be about the same as a predetermined power of 5 mW. Handle 210is an example implementation of handle 110. Circuits (e.g. 212, 216,218, 222, 224) of handle 210 may be controlled, in whole or in part, byprocessing circuit 220 to calibrate the magnitude of the power of lightprovided by green laser 212, red laser 216, and/or red laser 218.Circuits 430 and 460 combined are an example implementation of greenlaser 212. Processing circuit 220 and circuits 430 and 460 cooperatewith tester 130 to calibrate the magnitude of the power of light fromgreen laser 212.

During calibration, processing circuit 220 of handle 210 may perform theexample method shown in FIG. 6. To start calibration, processing circuit220 selects a predetermined power from memory 222. As discussed above,processing circuit 220 may receive and store one or more predeterminedpowers during manufacture, from tester 130 and/or from server 160.

In this example, processing circuit 220 in step 604 selects thepredetermined power for the U.S. region of operation. The maximummagnitude of the power of light for a laser diode in the U.S. is limitedto 5 mW. As an additional safeguard, the predetermined power for theU.S. may be specified to be 4.9 mW to ensure that the magnitude of thepower of light from a laser diode does not exceed the 5 mW limit.

In step 606, processing circuit 220 sets the value of the duty cycle ofa PWM signal to an initial duty cycle and sends the PWM signal to node480 to set the initial operating point of laser diode 450 andaccordingly set an initial magnitude of the power of light of laserdiode 450.

Tester 130 detects the light from laser diode 450 and measures themagnitude of the power of the light from laser diode 450. Processingcircuit 220 may control tester 130, in whole or part, so that the testerknows when to detect, measure, and/or report the magnitude of the powerof light measured. After measuring the magnitude of the power of lightfrom laser diode 450, tester 130 may send a message to processingcircuit 220 to report the magnitude of the power of light measured bytester 130. Tester 130 may detect, measure, and/or report aninstantaneous and/or average power of the magnitude of light provided bylaser diode 450.

In step 608, processing circuit 220 receives the message from tester130. When processing circuit 220 receives the message, processingcircuit 220 compares the measure magnitude of power to the valueretrieved from memory 222. Suppose that value reported by tester is 4.3mW.

In step 610, processing circuit 220 compares the value from the tester(e.g., 4.3 mW) to the value from memory 222 (e.g., 4.9 mW) anddetermines that the magnitude of the power of light from laser diode 450is not about equal to 4.9 mW.

Because the magnitude of light provided by laser diode 450 is not aboutequal to the predetermined power, control passes to step 612. In step612, processing circuit 220 determines that the measured power fromtester 130 is not greater than the predetermined power of 4.9 mW, socontrol passes to step 614. If the measured magnitude of light providedfrom laser diode 450 had been greater than the predetermined power, say5.0 mW, control would pass to step 616.

In step 614, processing circuit 220 increases the duty cycle of the PWMsignal impressed on node 480. Increasing the duty cycle of the PWMsignal increases the current that flows through laser diode 450 therebyincreasing the magnitude of light provided by laser diode 450.

In step 616, processing circuit 220 decreases the duty cycle of the PWMsignal impressed on node 480. Decreasing the cycle of the PWM signaldecreases the current that flows through laser diode 450 therebydecreasing the magnitude of light provided by laser diode 450.

Processing circuit 220 repeats steps 606 through 616 until step 610determines that the magnitude of the power of light provided by laserdiode 450 as reported by tester 130 is about the same as thepredetermined power. In this example, the predetermined power is 4.9 mW,so the magnitude of light provided by laser diode 450 is about the sameas the predetermined power if the magnitude of light provided by laserdiode 450 lies within the range of 4.41 mW-4.9 mW.

Once the magnitude of light provided by laser diode 450 as measured bytester 130 is about the same as the predetermined power, control movesto step 618.

In step 618, processing circuit 220 measures the magnitude of thevoltage at node 470. The magnitude of the voltage measured may be forexample 1.51V. The value of the measured voltage is the golden voltagefor the U.S. predetermined power.

In step 620, Processing circuit 220 saves value 1.51V in memory 222 andassociates the value 1.51 V to the predetermined power for the U.S.region. Because the magnitude of light provided by laser diode 450 hasbeen measured by tester 130 to be about equal to the predeterminedpower, processing circuit 220 knows that each time the magnitude of thevoltage at node 470 is about 1.51V that the magnitude of the power ofthe light provided by laser diode 450 is about 4.9 mW.

Processing circuit 220 executes steps 622 and 624 to repeat steps 604through 620 for each predetermined power and upper and/or lower range ofa predetermined range for each region where the laser diode may operate.

Because handle 210 includes more than one laser diode and each laserdiode needs to be calibrated separately, processing circuit 220 executessteps 626 and 628 to determine whether steps 604-622 need to be repeatedfor another laser diode, for example red laser 216 and/or red laser 218.

When calibration is complete, processing circuit 220 has determined thepredetermined power and possibly predetermined range for each laserdiode of handle 210 for each region where handle 210 may operate in thefield. As a result of calibration, a golden voltage has been determinedfor each predetermined power and possibly the upper and lower values foreach predetermined range for all regions where handle 210 may operate inthe field. The golden voltages have been stored in memory 222 for use inthe field to set and maintain the magnitude of the power of light fromthe laser diodes of handle 210 over temperature in any region.

A CEW may deliver a current to impede locomotion of a human or animaltarget when launched electrodes attach to the target. Electrodeplacement on a target (e.g., targeting) is aided by illumination by alaser diode of the predicted points of impact of the electrodes.Providing light from the laser diodes of a handle about equal to thepredetermined power for the region increases the visibility of the lightfrom the laser diodes and improves an operator's ability to target.

A server may contain information regarding the operating region of thehandle. A server may contain information regarding the maximum magnitudeof the power of light approved for a region and/or a range of themagnitude of the power of light for a region of operation.

A processing circuit of a handle may receive information regarding theoperating region of the handle. A processing circuit of a handle mayreceive information regarding the maximum magnitude of the power oflight allowed for a region of operation. A handle may store informationreceived from a server for use during field operation. A processingcircuit may correlate the maximum power of light for the region ofoperation to a calibrated golden voltage.

When a laser diode of a CEW is turned on in the field, a processingcircuit may retrieve from memory the golden voltage appropriate for theregion of operation. The processing circuit sets an initial operatingpoint of the laser diode by providing a PWM signal at a duty cycle tothe laser diode operating point circuit. The processing circuit measuresthe output voltage of the detector circuit and compares it to theappropriate golden voltage for the region. The processing circuitadjusts the duty cycle of the PWM signal and thereby the operating pointof the laser diode responsive to the comparison. The processing circuitrepeats adjusting the duty cycle of the PWM signal and comparing theoutput voltage of the detector circuit to the golden voltage until theoutput voltage of the detector circuit is about the same as the goldenvoltage.

When the output voltage of the detector circuit is at or about thegolden voltage, the magnitude of the power of light of the laser diodeis at the predetermined power for that region.

In the case where a region of operation of a handle is unknown, theprocessing circuit defaults to using the predetermined power and/orpredetermined range of the region with the lowest maximum output power.

For example, when handle 210 is powered on in the field, processingcircuit 220 sets the operation point of each laser diode and thereby themagnitude of power of light provided by each laser diode. Circuits (e.g.212, 216, 218, 222, 224) of handle 210 may be controlled, in whole or inpart, by processing circuit 220 to adjust the magnitude of the power oflight provided by green laser 212, red laser 216, and/or red laser 218.Circuits 430 and 460 combined are an example implementation of greenlaser 212. Processing circuit 220 may adjust signals (e.g., 480) tocircuits 430 and 460 to adjust the magnitude of the power of light fromgreen laser 212.

During field operation, processing circuit 220 of handle 210 may performthe example method shown in FIG. 7. To start laser diode operation,processing circuit 220 selects a golden voltage associated with theregion of operation from memory 222. As discussed above, processingcircuit 220 has previously stored golden voltages during calibration.

In this example, processing circuit 220 in step 704 retrieves frommemory 222 the golden voltage or a range of golden voltages for theregion of operation of handle 210. Processing circuit 220 may alsoretrieve information regarding the region of operation then use theregion information to retrieve the golden voltage or golden voltagerange.

With reference to Tables 1 and 2 above, the golden voltage retrievedfrom memory 222 may be a single value or two values that represent arange of values of the golden voltage. With reference to Table 1,processing circuit 220 may retrieve a single value for a golden voltage(e.g., V1P, V2P, V3P) then calculate the lower value of the goldenvoltage (e.g., V1Pm10, V2Pm10, V3Pm10) so that the power of light thatis provided by the laser diode is about the same as the predeterminedvalue for the region as defined above. For this example method 700,assume that memory 222 stores a single golden voltage for the region ofoperation (referred to as upper golden voltage), for example 1.51V, andprocessing circuit 220 calculates a voltage that represents thepredetermined power minus 10 percent (referred to as lower goldenvoltage), in this example 1.43V.

In step 706, processing circuit 220 sets the value of the duty cycle ofa PWM signal to an initial duty cycle and sends the PWM signal to node480 to set the initial operating point of laser diode 450 andaccordingly set an initial magnitude of the power of light of laserdiode 450.

In step 708, processing circuit 220 measures the magnitude of thevoltage at node 470. Suppose that value measured by processing circuit220 is 1.29V.

In step 712, processing circuit 220 compares the measured value (e.g.,1.29V) to the value of the upper golden voltage (e.g., 1.51V). If themeasured voltage at node 470 is greater than the upper golden voltage,the power provided by laser diode 450 is greater than the limit set forthe region, so control moves to step 718 to decrease the duty cycle ofthe PWM signal to decrease the power of the light provided by laserdiode 450. If the measured value is less than the upper golden voltage,as it is in this example, the power of the light from laser diode 450does not exceed the maximum limit for the region, but the power providedmay be too low, so control moves to step 714.

In step 714, processing circuit 220 compares the value of the voltagemeasured at node 470 (e.g., 1.29V) to the value of the lower goldenvoltage (e.g., 1.42V). If the measure value is less than the lowergolden voltage, as it is in this example, the power provided by laserdiode 450 is too low for the power to be about the same as thepredetermined limit or less than the lower range of power set for theregion. If the measured value is less than the lower golden voltage,control moves to step 716 to increase the duty cycle of the PWM signalto increase the power of the light provided by laser diode 450.

If the measured value is greater than or equal to the lower goldenvoltage, then voltage measured at node 470 is less than or equal to theupper golden voltage and is greater than or equal to the lower goldenvoltage, so power of the light provided by laser diode 450 is about thesame as the predetermined power or it lies within the predeterminedrange, so the operating point of laser diode 450 has been successfullyset for the region and temperature. Because the voltage measured at node470 lies within the range of upper and lower golden voltages, theprocess is complete and ends.

In step 716, processing circuit 220 increases the duty cycle of the PWMsignal impressed on node 480. Increasing the duty cycle of the PWMsignal increases the current that flows through laser diode 450 therebyincreasing the magnitude of light provided by laser diode 450.

In step 718, processing circuit 220 decreases the duty cycle of the PWMsignal impressed on node 480. Decreasing the duty cycle of the PWMsignal decreases the current that flows through laser diode 450 therebydecreasing the magnitude of light provided by laser diode 450.

Processing circuit 220 repeats steps 706 through 718 to set theoperating point of laser diode 450 so that the power of light providedby laser diode 450 is appropriate for the region of operation of thelaser diode.

Because handle 210 includes more than one laser diode and each laserdiode needs to be monitored and adjusted separately.

Performing method 700 to set the power provided by the laser diode takesonly milliseconds. Method 700 is performed when handle 210 is power up(e.g., safety off). Method 700 may further be performed periodicallywhile handle 210 is power up to adjust the power of the light providedby the diode responsive to temperature changes.

The operating efficiency of a laser diode, ratio of the magnitude of thepower output of light to the electrical input power, changes atdifferent operating points of the laser diode. As the magnitude of thepower of light provided by a laser diode increases the efficiency of thelaser diode also increases. For example, the laser diode of thecharacteristic curve of FIG. 3 requires 58 mA to provide 5 mW of power,but for a small increase of 7 mA the laser diode provides 10 mW ofpower. To improve the battery life of a CEW, a laser diode may beoperated at a higher power to more efficiently use the power from thebattery; however, operating at a higher power may result in the laserdiode providing light at a power that is greater than the limit for aregion.

The power limits for a region are expressed as the average power oflight provided by a diode. A laser diode may provide an average powerthat lies within the limit by switching the laser diode between twooperating points. One operating point may provide light at a power thatexceeds the regional limit and the other operating point may providelight at a power that is significantly less than the regional limit, sothat the power output over time is less than or equal to the regionallimit.

Referring to FIG. 4, laser diode 450 may be switched between operatingpoints by changing the duty cycle of the PWM signal provided to node480. For example, during a portion of a period of time, the PWM signalmay have a higher duty cycle to operate laser diode at a higher power(e.g., higher instantaneous power) that exceeds the regional limit(e.g., 10 mW) and for the remaining portion of the period of time at alower duty cycle to operate the laser diode at a lower power (e.g.,lower instantaneous power) (e.g., 3 mW) that is less than the regionallimit, so that the average power provided by laser diode 450 over theperiod is about the same as the regional limit (e.g., 5 mW).

Another method for operating a laser diode to provide light at anaverage power over a period is to operate the laser diode at a power(e.g., instantaneous power) that is greater than the regional limited,to increase the operating efficiency of the laser diode, then switch thelaser diode off and on at a duty cycle so that the average powerprovided by the laser diode is about the same as the predetermined powerfor the region. While the laser diode is off, it provides not light.

Altering the operation of the diode to provide an average power isreferred to herein as power modulation. The duty cycles for changing theoperating point of the laser diode or for turning the laser diode on andoff may be determined during calibration. Power modulation to provide apredetermined power may relate to a golden voltage, so that detecting avoltage and comparing the detected voltage to the golden voltage issufficient to determine the power of light provided by the laser diode.

Circuit 800 of FIG. 8 is an example of a circuit that uses a PWM signalto turn laser diode 450 on and off at a duty cycle to perform powermodulation. Circuit 830 sets the operating point of laser diode 450 asdiscussed above with respect to circuit 400 and in particular circuit430 in addition to switching laser diode 450 on and off.

For example, processing circuit 220 provides a PWM signal to node 480 toset the operating point of laser diode 450. Processing circuit 220further provides a PWM signal to node 820. The PWM signal on node 820controls switch (e.g., FET transistor) 810 to enable (e.g., switch on)laser diode 450 and to disable (e.g., switch off) laser diode 450. Whenlaser diode 450 is switched on, current flows through laser diode 450and laser diode 450 provides light at the power (e.g., power greaterthan regional limit) set by the PWM signal impressed on node 480. Whenlaser diode 450 is switched off, no current flows through laser diode450 and laser diode 450 provides no light (e.g., zero power).

The ratio of the portion of time that laser diode 450 is on for a periodof time determines the average power of light provided by laser diode450 during the period of time. The average power of the light providedby laser diode 450 may be increased by increasing the portion of timethat laser diode 450 is on during the period. The average power of thelight provided by laser diode 450 may be decreased by decreasing theportion of the time that laser diode 450 is on during the period. Theduty cycle of the PWM signal impressed on node 820 determines theportion of time that laser diode 450 is on during the period of the PWMsignal.

During calibration, tester 130 measures and reports the average power ofthe light provided by laser diode 450 for the operating point set by thePWM signal on node 480 and the power modulation set by the PWM signal onnode 820. Photo detector 462 provides a current that is proportional tothe power of the light provided by laser diode 450 while it is turned onand no current when laser diode 450 is turned off. Capacitor 466 incombination with resistor 464 has a response time that is slower than(e.g., an order of magnitude) the period of the PWM signals on node 480and/or node 820 so that the voltage across capacitor 466 and resistor464 is not affected by the changes and represents the golden voltagewhen laser diode 450 is providing the desired average power as measuredby tester 130.

Circuit 900 of FIG. 9 is similar to circuit 800. Circuit 900 differsfrom circuit 800 only in how power modulation PWM signal 920 isgenerated. In circuit 900, PWM signal 480 drives the input ofdivide-by-two counter 912. The output of divide-by-two counter 912drives node 920. The PWM signal on node 920 controls switch (e.g., FETtransistor) 810 to provide power modulation of laser diode 450.

The relationship of PWM signals 480 and 920 are illustrated in FIG. 10.The duration of the on-time (e.g., high signal) of PWM signal 920 isequal to the period of PWM signal 480. The on-time of PWM signal 920represents the time when laser diode 450 is switched on. The duration ofthe off-time (e.g., low signal) of signal 920 is also equal to theperiod of PWM signal 480. The off-time of PWM signal 920 represents thetime when laser diode 450 is switched off. The duty cycle of PWM signal920 is fixed at 50 percent.

Circuit 1100 is an example of a circuit that sets the operating point oftwo laser diodes and detects the magnitude of output power of the lightof each laser diode one at a time. Operation of the two laser diodes arenot concurrent. Processing circuit 220 selects which laser diode, laserdiode 1150 or laser diode 1152, is operational, allowing only one laserdiode to operate at a time. Circuit 1100 performs the functions of acircuit that sets the operating point of a laser diode duringcalibration and operation in the field as discussed above. Circuit 1100further performs the functions of a detector circuit discussed above.Circuit 1100 includes processing circuit 220, enable circuit 1190,operating point circuit 1130, and detector circuit 1160. Circuits 1130,1160, and 1190 combined are an example implementation of red laser 216and red laser 218.

Processing circuit 220 performs the functions of a processing circuitdiscussed above. Processing circuit 220 uses signal 1170 and signal 1172to turn laser diode 1150 and laser diode 1152 respectively on and off.Processing circuit 220 provides a signal on node 1170 to control switch1110 to enable laser diode 1150 by connecting the anode of laser diode1150 to Vcc (e.g. power) and to disable laser diode 1150 bydisconnecting the anode of laser diode from Vcc. When laser diode 1150is switched on, current flows through laser diode 1150 and laser diode1150 provides light at a power set by the duty cycle of the PWM signalimpressed on node 1180. When laser diode 1150 is switched off, nocurrent flows through laser diode 1150 and laser diode 1150 provides nolight.

Operating point circuit 1130 sets the operating point of the laser diodethat is enabled by controlling the voltage at the cathode of laser diode1150 or laser diode 1152 by providing a PWM signal on node 1180.Reducing the voltage on the cathode (node 1140) of laser diode 1150 orlaser diode 1152 increases current flow through the laser diode.Decreasing the duty cycle (e.g., less on-time) of signal 1180 increasesthe voltage on node 1140 and thereby decreases the current flow throughlaser diode 1150 or laser diode 1152.

Because laser diodes 1150 and 1152 do not operate concurrently,processing circuit 220 may calibrate and operate each laser diodeseparately. Detector circuit 1160 generates a voltage at node 1170 thatrelates to the power of the light provided by the laser diode that isenabled. Each laser diode/photo detector pair (e.g., 1150/1162,1152/1168) may be calibrated to find a golden voltage as discussedabove. Each laser diode/photo detector pair is associated with its owngolden voltage. Golden voltages may differ for each laser diode/photodetector pair.

Photo detectors 1162 and 1168 provide a current that is proportional tothe magnitude of the power of the light provided by laser diodes 1150and 1152 respectively. Capacitor 1166 in combination with resistor 1164has a response time that is slower than (e.g., an order of magnitude)the period of the PWM signal on node 1180 so that the voltage acrosscapacitor 1166 and resistor 1164 is not affected by the changes andrepresents the golden voltage when laser diode 1150 or 1152 is providingthe desired average power as measured by tester 130.

The foregoing description discusses embodiments, which may be changed ormodified without departing from the scope of the invention as defined inthe claims. Examples listed in parentheses may be used in thealternative or in any practical combination. As used in thespecification and claims, the words ‘comprising’, ‘comprises’,‘including’, ‘includes’, ‘having’, and ‘has’ introduce an open-endedstatement of component structures and/or functions. In the specificationand claims, the words ‘a’ and ‘an’ are used as indefinite articlesmeaning ‘one or more’. When a descriptive phrase includes a series ofnouns and/or adjectives, each successive word is intended to modify theentire combination of words preceding it. For example, a black dog houseis intended to mean a house for a black dog. While for the sake ofclarity of description, several specific embodiments of the inventionhave been described, the scope of the invention is intended to bemeasured by the claims as set forth below. In the claims, the term“provided” is used to definitively identify an object that not a claimedelement of the invention but an object that performs the function of aworkpiece that cooperates with the claimed invention. For example, inthe claim “an apparatus for aiming a provided barrel, the apparatuscomprising: a housing, the barrel positioned in the housing”, the barrelis not a claimed element of the apparatus, but an object that cooperateswith the “housing” of the “apparatus” by being positioned in the“housing”. The invention includes any practical combination of thestructures and methods disclosed. While for the sake of clarity ofdescription several specifics embodiments of the invention have beendescribed, the scope of the invention is intended to be measured by theclaims as set forth below.

The location indicators “herein”, “hereunder”, “above”, “below”, orother word that refer to a location, whether specific or general, in thespecification shall be construed to refer to any location in thespecification where the location is before or after the locationindicator.

What is claimed is:
 1. A weapon that cooperates with a provided serverfor selecting an operation of the weapon, the weapon comprising: aprocessing circuit; a laser diode that provides a light; a memory; and acommunications circuit; wherein the processing circuit executes a storedprogram from the memory to: receive a message via the communicationscircuit from the server, the message includes information regarding afirst limit, the first limit approved for a first region where theweapon is located; retrieve indicia from the memory in accordance withthe first limit; and operate the laser diode in accordance with theindicia whereby a magnitude of the power of the light provided by thelaser diode is less than or equal to the first limit.
 2. The weapon ofclaim 1 wherein prior to receipt of the message, the magnitude of thepower of the light provided by the laser diode is about equal to a limitapproved for all regions.
 3. The weapon of claim 1 wherein theprocessing circuit further executes the stored program to store in thememory the first limit received in the message.
 4. The weapon of claim 1wherein the indicia are stored during calibration of the laser diode. 5.The weapon of claim 1 wherein: the first limit corresponds to a maximummagnitude for the first region; a second limit corresponds to a maximummagnitude for a second region; the first limit is greater than thesecond limit; and the magnitude of the power of the light provided bythe laser diode is less than the first limit and greater than the secondlimit.
 6. A method performed by a weapon for calibrating a power of alight provided by a laser diode of the weapon, the method comprising:receiving a message from a server regarding a first limit, the firstlimit approved for a first region where the weapon is located;retrieving indicia from a memory of the weapon in accordance with thefirst limit; and operating the laser diode in accordance with theindicia whereby a magnitude of the power of the light provided by thelaser diode is less than or equal to the first limit.
 7. The method ofclaim 6 wherein retrieving comprises retrieving a magnitude of a voltagerelated to the first limit.
 8. The method of claim 6 wherein: retrievingcomprises retrieving a magnitude of a voltage related to the firstlimit; and operating comprises adjusting a duty cycle of a signal sothat a processing circuit of the weapon determines that a magnitude of avoltage across a resistor is about equal to the voltage related to thefirst limit.
 9. The method of claim 6 wherein receiving comprises:determining a geographic location of the weapon; providing thegeographic location to the server; and receiving the message from theserver regarding the first limit.
 10. A weapon comprising: a processingcircuit; a laser diode; and a memory; wherein the processing circuitexecutes a stored program from the memory to: retrieve from memory alimit, the limit approved for a region, the weapon located in theregion; in accordance with the limit, retrieve from memory indicia; andoperate the laser diode in accordance with the indicia so that amagnitude of a power of a light provided by the laser diode is less thanor equal to the limit.
 11. The weapon of claim 10 further comprises aswitch, wherein the processing circuit retrieves the indicia in responseto a signal from the switch.
 12. The weapon of claim 10 wherein theindicia are stored during calibration of the laser diode.
 13. The weaponof claim 10 wherein: the indicia include a magnitude of a first voltage,the first voltage related to the limit; and the processing circuitexecutes the stored program to adjust a duty cycle of a signal thatoperates the laser diode to maintain a magnitude of a second voltageacross a resistor to be about equal to the magnitude of the firstvoltage so that the magnitude of the power of the light provided by thelaser diode is less than or equal to the limit.
 14. The weapon of claim13 further comprising a photo detector, wherein: the light provided bythe laser diode causes a current to flow through the photo detector, thecurrent is related to the magnitude of the power of the light providedby the laser diode; and the magnitude of the second voltage is relatedto the current.
 15. The weapon of claim 14 wherein the current flowsthrough the resistor to induce the second voltage.
 16. The weapon ofclaim 13 wherein: if the magnitude of the second voltage is greater thanthe magnitude of the first voltage, the processing circuit decreases theduty cycle of the signal; and if the magnitude of the second voltage isless than the magnitude of the first voltage, the processing circuitincreases the duty cycle of the signal.
 17. The method of claim 8wherein the voltage across the resistor is related to the magnitude ofthe power of the light provided by the laser diode.
 18. The method ofclaim 8 further comprising: detecting the magnitude of the voltageacross the resistor; and adjusting in accordance with detecting.
 19. Themethod of claim 8 further comprising: detecting the light provided bythe laser diode; in accordance with detecting, producing a current, thecurrent related to the magnitude of the power of the light provided bythe laser diode; and directing the current through the resistor toinduce the voltage across the resistor.
 20. The method of claim 9wherein providing and receiving comprise transmitting and receivingrespectively via a long-range communication link.